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* signal.c: fix erroneous syscall kernel-docRandy Dunlap2011-04-081-2/+2
| | | | | | | | Fix erroneous syscall kernel-doc comments in kernel/signal.c. Reported-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6Linus Torvalds2011-04-071-1/+1
|\ | | | | | | | | * 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6: Fix common misspellings
| * Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | | | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* | kernel/signal.c: add kernel-doc notation to syscallsRandy Dunlap2011-04-041-2/+63
| | | | | | | | | | | | | | Add kernel-doc to syscalls in signal.c. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kernel/signal.c: fix typos and coding styleRandy Dunlap2011-04-041-42/+48
|/ | | | | | | | | | | | | | | General coding style and comment fixes; no code changes: - Use multi-line-comment coding style. - Put some function signatures completely on one line. - Hyphenate some words. - Spell Posix as POSIX. - Correct typos & spellos in some comments. - Drop trailing whitespace. - End sentences with periods. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Relax si_code check in rt_sigqueueinfo and rt_tgsigqueueinfoRoland Dreier2011-03-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Commit da48524eb206 ("Prevent rt_sigqueueinfo and rt_tgsigqueueinfo from spoofing the signal code") made the check on si_code too strict. There are several legitimate places where glibc wants to queue a negative si_code different from SI_QUEUE: - This was first noticed with glibc's aio implementation, which wants to queue a signal with si_code SI_ASYNCIO; the current kernel causes glibc's tst-aio4 test to fail because rt_sigqueueinfo() fails with EPERM. - Further examination of the glibc source shows that getaddrinfo_a() wants to use SI_ASYNCNL (which the kernel does not even define). The timer_create() fallback code wants to queue signals with SI_TIMER. As suggested by Oleg Nesterov <oleg@redhat.com>, loosen the check to forbid only the problematic SI_TKILL case. Reported-by: Klaus Dittrich <kladit@arcor.de> Acked-by: Julien Tinnes <jln@google.com> Cc: <stable@kernel.org> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* userns: allow killing tasks in your own or child usernsSerge E. Hallyn2011-03-231-8/+22
| | | | | | | | | | | | | | | | | | | | | | Changelog: Dec 8: Fixed bug in my check_kill_permission pointed out by Eric Biederman. Dec 13: Apply Eric's suggestion to pass target task into kill_ok_by_cred() for clarity Dec 31: address comment by Eric Biederman: don't need cred/tcred in check_kill_permission. Jan 1: use const cred struct. Jan 11: Per Bastian Blank's advice, clean up kill_ok_by_cred(). Feb 16: kill_ok_by_cred: fix bad parentheses Feb 23: per akpm, let compiler inline kill_ok_by_cred Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Prevent rt_sigqueueinfo and rt_tgsigqueueinfo from spoofing the signal codeJulien Tinnes2011-03-211-4/+12
| | | | | | | | | | | | | | | | | | | | | | Userland should be able to trust the pid and uid of the sender of a signal if the si_code is SI_TKILL. Unfortunately, the kernel has historically allowed sigqueueinfo() to send any si_code at all (as long as it was negative - to distinguish it from kernel-generated signals like SIGILL etc), so it could spoof a SI_TKILL with incorrect siginfo values. Happily, it looks like glibc has always set si_code to the appropriate SI_QUEUE, so there are probably no actual user code that ever uses anything but the appropriate SI_QUEUE flag. So just tighten the check for si_code (we used to allow any negative value), and add a (one-time) warning in case there are binaries out there that might depend on using other si_code values. Signed-off-by: Julien Tinnes <jln@google.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signals: annotate lock context change on ptrace_stop()Namhyung Kim2010-10-271-0/+2
| | | | | | | | | | | | ptrace_stop() releases and regrabs current->sighand->siglock but was missing proper annotation. Add it. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signals: annotate lock_task_sighand()Namhyung Kim2010-10-271-1/+2
| | | | | | | | | | | | | | | lock_task_sighand() grabs sighand->siglock in case of returning non-NULL but unlock_task_sighand() releases it unconditionally. This leads sparse to complain about the lock context imbalance. Rename and wrap lock_task_sighand() using __cond_lock() macro to make sparse happy. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* HWPOISON: Copy si_addr_lsb to userAndi Kleen2010-10-071-0/+8
| | | | | | | | | | | The original hwpoison code added a new siginfo field si_addr_lsb to pass the granuality of the fault address to user space. Unfortunately this field was never copied to user space. Fix this here. I added explicit checks for the MCEERR codes to avoid having to patch all potential callers to initialize the field. Signed-off-by: Andi Kleen <ak@linux.intel.com>
* CRED: Fix RCU warning due to previous patch fixing __task_cred()'s checksDavid Howells2010-08-041-3/+6
| | | | | | | | | | | | | | | | | | | | | | | Commit 8f92054e7ca1 ("CRED: Fix __task_cred()'s lockdep check and banner comment") fixed the lockdep checks on __task_cred(). This has shown up a place in the signalling code where a lock should be held - namely that check_kill_permission() requires its callers to hold the RCU lock. Fix group_send_sig_info() to get the RCU read lock around its call to check_kill_permission(). Without this patch, the following warning can occur: =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- kernel/signal.c:660 invoked rcu_dereference_check() without protection! ... Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exit: change zap_other_threads() to count sub-threadsOleg Nesterov2010-05-271-8/+9
| | | | | | | | | | | | | | | | | Change zap_other_threads() to return the number of other sub-threads found on ->thread_group list. Other changes are cosmetic: - change the code to use while_each_thread() helper - remove the obsolete comment about SIGKILL/SIGSTOP Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signals: check_kill_permission(): don't check creds if same_thread_group()Oleg Nesterov2010-05-271-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrew Tridgell reports that aio_read(SIGEV_SIGNAL) can fail if the notification from the helper thread races with setresuid(), see http://samba.org/~tridge/junkcode/aio_uid.c This happens because check_kill_permission() doesn't permit sending a signal to the task with the different cred->xids. But there is not any security reason to check ->cred's when the task sends a signal (private or group-wide) to its sub-thread. Whatever we do, any thread can bypass all security checks and send SIGKILL to all threads, or it can block a signal SIG and do kill(gettid(), SIG) to deliver this signal to another sub-thread. Not to mention that CLONE_THREAD implies CLONE_VM. Change check_kill_permission() to avoid the credentials check when the sender and the target are from the same thread group. Also, move "cred = current_cred()" down to avoid calling get_current() twice. Note: David Howells pointed out we could relax this even more, the CLONE_SIGHAND (without CLONE_THREAD) case probably does not need these checks too. Roland said: : The glibc (libpthread) that does set*id across threads has : been in use for a while (2.3.4?), probably in distro's using kernels as old : or older than any active -stable streams. In the race in question, this : kernel bug is breaking valid POSIX application expectations. Reported-by: Andrew Tridgell <tridge@samba.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Eric Paris <eparis@parisplace.org> Cc: Jakub Jelinek <jakub@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Roland McGrath <roland@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: <stable@kernel.org> [all kernel versions] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kdb: core for kgdb back end (2 of 2)Jason Wessel2010-05-201-0/+40
| | | | | | | | | | This patch contains the hooks and instrumentation into kernel which live outside the kernel/debug directory, which the kdb core will call to run commands like lsmod, dmesg, bt etc... CC: linux-arch@vger.kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Martin Hicks <mort@sgi.com>
* kernel core: use helpers for rlimitsJiri Slaby2010-03-061-1/+1
| | | | | | | | | | | | | | | | Make sure compiler won't do weird things with limits. E.g. fetching them twice may return 2 different values after writable limits are implemented. I.e. either use rlimit helpers added in commit 3e10e716abf3 ("resource: add helpers for fetching rlimits") or ACCESS_ONCE if not applicable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Prioritize synchronous signals over 'normal' signalsLinus Torvalds2010-03-031-13/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes sure that we pick the synchronous signals caused by a processor fault over any pending regular asynchronous signals sent to use by [t]kill(). This is not strictly required semantics, but it makes it _much_ easier for programs like Wine that expect to find the fault information in the signal stack. Without this, if a non-synchronous signal gets picked first, the delayed asynchronous signal will have its signal context pointing to the new signal invocation, rather than the instruction that caused the SIGSEGV or SIGBUS in the first place. This is not all that pretty, and we're discussing making the synchronous signals more explicit rather than have these kinds of implicit preferences of SIGSEGV and friends. See for example http://bugzilla.kernel.org/show_bug.cgi?id=15395 for some of the discussion. But in the meantime this is a simple and fairly straightforward work-around, and the whole if (x & Y) x &= Y; thing can be compiled into (and gcc does do it) just three instructions: movq %rdx, %rax andl $Y, %eax cmovne %rax, %rdx so it is at least a simple solution to a subtle issue. Reported-and-tested-by: Pavel Vilim <wylda@volny.cz> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/signal.c: fix kernel information leak with print-fatal-signals=1Andi Kleen2010-01-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | When print-fatal-signals is enabled it's possible to dump any memory reachable by the kernel to the log by simply jumping to that address from user space. Or crash the system if there's some hardware with read side effects. The fatal signals handler will dump 16 bytes at the execution address, which is fully controlled by ring 3. In addition when something jumps to a unmapped address there will be up to 16 additional useless page faults, which might be potentially slow (and at least is not very efficient) Fortunately this option is off by default and only there on i386. But fix it by checking for kernel addresses and also stopping when there's a page fault. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2009-12-191-11/+14
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sys: Fix missing rcu protection for __task_cred() access signals: Fix more rcu assumptions signal: Fix racy access to __task_cred in kill_pid_info_as_uid()
| * signals: Fix more rcu assumptionsThomas Gleixner2009-12-101-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 1) Remove the misleading comment in __sigqueue_alloc() which claims that holding a spinlock is equivalent to rcu_read_lock(). 2) Add a rcu_read_lock/unlock around the __task_cred() access in __sigqueue_alloc() This needs to be revisited to remove the remaining users of read_lock(&tasklist_lock) but that's outside the scope of this patch. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20091210004703.269843657@linutronix.de>
| * signal: Fix racy access to __task_cred in kill_pid_info_as_uid()Thomas Gleixner2009-12-101-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | kill_pid_info_as_uid() accesses __task_cred() without being in a RCU read side critical section. tasklist_lock is not protecting that when CONFIG_TREE_PREEMPT_RCU=y. Convert the whole tasklist_lock section to rcu and use lock_task_sighand to prevent the exit race. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20091210004703.232302055@linutronix.de> Acked-by: Oleg Nesterov <oleg@redhat.com>
* | signals: check ->group_stop_count after tracehook_get_signal()Oleg Nesterov2009-12-161-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Move the call to do_signal_stop() down, after tracehook call. This makes ->group_stop_count condition visible to tracers before do_signal_stop() will participate in this group-stop. Currently the patch has no effect, tracehook_get_signal() always returns 0. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signals: kill force_sig_specific()Oleg Nesterov2009-12-161-6/+0
| | | | | | | | | | | | | | | | | | | | Kill force_sig_specific(), this trivial wrapper has no callers. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signals: cosmetic, collect_signal: use SI_USEROleg Nesterov2009-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Trivial, s/0/SI_USER/ in collect_signal() for grep. This is a bit confusing, we don't know the source of this signal. But we don't care, and "info->si_code = 0" is imho worse. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signals: send_signal: use si_fromuser() to detect from_ancestor_nsOleg Nesterov2009-12-161-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change send_signal() to use si_fromuser(). From now SEND_SIG_NOINFO triggers the "from_ancestor_ns" check. This fixes reparent_thread()->group_send_sig_info(pdeath_signal) behaviour, before this patch send_signal() does not detect the cross-namespace case when the child of the dying parent belongs to the sub-namespace. This patch can affect the behaviour of send_sig(), kill_pgrp() and kill_pid() when the caller sends the signal to the sub-namespace with "priv == 0" but surprisingly all callers seem to use them correctly, including disassociate_ctty(on_exit). Except: drivers/staging/comedi/drivers/addi-data/*.c incorrectly use send_sig(priv => 0). But his is minor and should be fixed anyway. Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signals: SEND_SIG_NOINFO should be considered as SI_FROMUSER()Oleg Nesterov2009-12-161-3/+13
|/ | | | | | | | | | | | | | | | | | | | | | | No changes in compiled code. The patch adds the new helper, si_fromuser() and changes check_kill_permission() to use this helper. The real effect of this patch is that from now we "officially" consider SEND_SIG_NOINFO signal as "from user-space" signals. This is already true if we look at the code which uses SEND_SIG_NOINFO, except __send_signal() has another opinion - see the next patch. The naming of these special SEND_SIG_XXX siginfo's is really bad imho. From __send_signal()'s pov they mean SEND_SIG_NOINFO from user SEND_SIG_PRIV from kernel SEND_SIG_FORCED no info Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Reviewed-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2009-12-051-7/+20
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (470 commits) x86: Fix comments of register/stack access functions perf tools: Replace %m with %a in sscanf hw-breakpoints: Keep track of user disabled breakpoints tracing/syscalls: Make syscall events print callbacks static tracing: Add DEFINE_EVENT(), DEFINE_SINGLE_EVENT() support to docbook perf: Don't free perf_mmap_data until work has been done perf_event: Fix compile error perf tools: Fix _GNU_SOURCE macro related strndup() build error trace_syscalls: Remove unused syscall_name_to_nr() trace_syscalls: Simplify syscall profile trace_syscalls: Remove duplicate init_enter_##sname() trace_syscalls: Add syscall_nr field to struct syscall_metadata trace_syscalls: Remove enter_id exit_id trace_syscalls: Set event_enter_##sname->data to its metadata trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit perf_event: Initialize data.period in perf_swevent_hrtimer() perf probe: Simplify event naming perf probe: Add --list option for listing current probe events perf probe: Add argv_split() from lib/argv_split.c perf probe: Move probe event utility functions to probe-event.c ...
| * tracepoint: Add signal loss eventsMasami Hiramatsu2009-11-261-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add signal_overflow_fail and signal_lose_info tracepoints for signal-lost events. Changes in v3: - Add docbook style comments Changes in v2: - Use siginfo string macro Suggested-by: Roland McGrath <roland@redhat.com> Reviewed-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <20091124215658.30449.9934.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * tracepoint: Add signal deliver eventMasami Hiramatsu2009-11-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a tracepoint where a process gets a signal. This tracepoint shows signal-number, sa-handler and sa-flag. Changes in v3: - Add docbook style comments Changes in v2: - Add siginfo argument - Fix comment Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Reviewed-by: Jason Baron <jbaron@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <20091124215651.30449.20926.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * tracepoint: Move signal sending tracepoint to events/signal.hMasami Hiramatsu2009-11-261-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move signal sending event to events/signal.h. This patch also renames sched_signal_send event to signal_generate. Changes in v4: - Fix a typo of task_struct pointer. Changes in v3: - Add docbook style comments Changes in v2: - Add siginfo argument - Add siginfo storing macro Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Reviewed-by: Jason Baron <jbaron@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Oleg Nesterov <oleg@redhat.com> LKML-Reference: <20091124215645.30449.60208.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | signal: Print warning message when dropping signalsNaohiro Ooiwa2009-11-091-13/+33
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the system has too many timers or too many aggregate queued signals, the EAGAIN error is returned to application from kernel, including timer_create() [POSIX.1b]. It means that the app exceeded the limit of pending signals, but in general application writers do not expect this outcome and the current silent failure can cause rare app failures under very high load. This patch adds a new message when we reach the limit and if print_fatal_signals is enabled: task/1234: reached RLIMIT_SIGPENDING, dropping signal If you see this message and your system behaved unexpectedly, you can run following command to lift the limit: # ulimit -i unlimited With help from Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>. Signed-off-by: Naohiro Ooiwa <nooiwa@miraclelinux.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Roland McGrath <roland@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: oleg@redhat.com LKML-Reference: <4AF6E7E2.9080406@miraclelinux.com> [ Modified a few small details, gave surrounding code some love. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* signals: inline __fatal_signal_pendingRoland McGrath2009-09-241-6/+0
| | | | | | | | | | | | | | __fatal_signal_pending inlines to one instruction on x86, probably two instructions on other machines. It takes two longer x86 instructions just to call it and test its return value, not to mention the function itself. On my random x86_64 config, this saved 70 bytes of text (59 of those being __fatal_signal_pending itself). Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signals: introduce do_send_sig_info() helperOleg Nesterov2009-09-241-29/+27
| | | | | | | | | | | | | | | | | | Introduce do_send_sig_info() and convert group_send_sig_info(), send_sig_info(), do_send_specific() to use this helper. Hopefully it will have more users soon, it allows to specify specific/group behaviour via "bool group" argument. Shaves 80 bytes from .text. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stephane eranian <eranian@googlemail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signals: tracehook_notify_jctl changeRoland McGrath2009-09-241-50/+47
| | | | | | | | | | | | | | | | | | | | | This changes tracehook_notify_jctl() so it's called with the siglock held, and changes its argument and return value definition. These clean-ups make it a better fit for what new tracing hooks need to check. Tracing needs the siglock here, held from the time TASK_STOPPED was set, to avoid potential SIGCONT races if it wants to allow any blocking in its tracing hooks. This also folds the finish_stop() function into its caller do_signal_stop(). The function is short, called only once and only unconditionally. It aids readability to fold it in. [oleg@redhat.com: do not call tracehook_notify_jctl() in TASK_STOPPED state] [oleg@redhat.com: introduce tracehook_finish_jctl() helper] Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ptrace: __ptrace_detach: do __wake_up_parent() if we reap the traceeOleg Nesterov2009-09-241-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bug is old, it wasn't cause by recent changes. Test case: static void *tfunc(void *arg) { int pid = (long)arg; assert(ptrace(PTRACE_ATTACH, pid, NULL, NULL) == 0); kill(pid, SIGKILL); sleep(1); return NULL; } int main(void) { pthread_t th; long pid = fork(); if (!pid) pause(); signal(SIGCHLD, SIG_IGN); assert(pthread_create(&th, NULL, tfunc, (void*)pid) == 0); int r = waitpid(-1, NULL, __WNOTHREAD); printf("waitpid: %d %m\n", r); return 0; } Before the patch this program hangs, after this patch waitpid() correctly fails with errno == -ECHILD. The problem is, __ptrace_detach() reaps the EXIT_ZOMBIE tracee if its ->real_parent is our sub-thread and we ignore SIGCHLD. But in this case we should wake up other threads which can sleep in do_wait(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Vitaly Mayatskikh <vmayatsk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* do_sigaltstack: small cleanupsLinus Torvalds2009-08-011-4/+6
| | | | | | | | | The previous commit ("do_sigaltstack: avoid copying 'stack_t' as a structure to user space") fixed a real bug. This one just cleans up the copy from user space to that gcc can generate better code for it (and so that it looks the same as the later copy back to user space). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* do_sigaltstack: avoid copying 'stack_t' as a structure to user spaceLinus Torvalds2009-08-011-7/+8
| | | | | | | | | | | | | | | | | | Ulrich Drepper correctly points out that there is generally padding in the structure on 64-bit hosts, and that copying the structure from kernel to user space can leak information from the kernel stack in those padding bytes. Avoid the whole issue by just copying the three members one by one instead, which also means that the function also can avoid the need for a stack frame. This also happens to match how we copy the new structure from user space, so it all even makes sense. [ The obvious solution of adding a memset() generates horrid code, gcc does really stupid things. ] Reported-by: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ptrace: do_notify_parent_cldstop: fix the wrong ->nsproxy usageOleg Nesterov2009-06-181-1/+1
| | | | | | | | | | | | | | | | If the non-traced sub-thread calls do_notify_parent_cldstop(), we send the notification to group_leader->real_parent and we report group_leader's pid. But, if group_leader is traced we use the wrong ->parent->nsproxy->pid_ns, the tracer and parent can live in different namespaces. Change the code to use "parent" instead of tsk->parent. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ptrace: do not use task->ptrace directly in core kernelOleg Nesterov2009-06-181-5/+5
| | | | | | | | | | | | | | | No functional changes. - Nobody except ptrace.c & co should use ptrace flags directly, we have task_ptrace() for that. - No need to specially check PT_PTRACED, we must not have other PT_ bits set without PT_PTRACED. And no need to know this flag exists. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* signal: fix __send_signal() false positive kmemcheck warningVegard Nossum2009-06-151-3/+8
| | | | | | | | | | | | | | This false positive is due to field padding in struct sigqueue. When this dynamically allocated structure is copied to the stack (in arch- specific delivery code), kmemcheck sees a read from the padding, which is, naturally, uninitialized. Hide the false positive using the __GFP_NOTRACK_FALSE_POSITIVE flag. Also made the rlimit override code a bit clearer by introducing a new variable. Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-06-111-3/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (44 commits) nommu: Provide mmap_min_addr definition. TOMOYO: Add description of lists and structures. TOMOYO: Remove unused field. integrity: ima audit dentry_open failure TOMOYO: Remove unused parameter. security: use mmap_min_addr indepedently of security models TOMOYO: Simplify policy reader. TOMOYO: Remove redundant markers. SELinux: define audit permissions for audit tree netlink messages TOMOYO: Remove unused mutex. tomoyo: avoid get+put of task_struct smack: Remove redundant initialization. integrity: nfsd imbalance bug fix rootplug: Remove redundant initialization. smack: do not beyond ARRAY_SIZE of data integrity: move ima_counts_get integrity: path_check update IMA: Add __init notation to ima functions IMA: Minimal IMA policy and boot param for TCB IMA policy selinux: remove obsolete read buffer limit from sel_read_bool ...
| * Merge branch 'master' into nextJames Morris2009-05-081-14/+49
| |\
| * | SELinux: Don't flush inherited SIGKILL during execve()David Howells2009-04-301-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't flush inherited SIGKILL during execve() in SELinux's post cred commit hook. This isn't really a security problem: if the SIGKILL came before the credentials were changed, then we were right to receive it at the time, and should honour it; if it came after the creds were changed, then we definitely should honour it; and in any case, all that will happen is that the process will be scrapped before it ever returns to userspace. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* | | Merge branch 'tracing-for-linus' of ↵Linus Torvalds2009-06-101-3/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits) Revert "x86, bts: reenable ptrace branch trace support" tracing: do not translate event helper macros in print format ftrace/documentation: fix typo in function grapher name tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK tracing: add protection around module events unload tracing: add trace_seq_vprint interface tracing: fix the block trace points print size tracing/events: convert block trace points to TRACE_EVENT() ring-buffer: fix ret in rb_add_time_stamp ring-buffer: pass in lockdep class key for reader_lock tracing: add annotation to what type of stack trace is recorded tracing: fix multiple use of __print_flags and __print_symbolic tracing/events: fix output format of user stack tracing/events: fix output format of kernel stack tracing/trace_stack: fix the number of entries in the header ring-buffer: discard timestamps that are at the start of the buffer ring-buffer: try to discard unneeded timestamps ring-buffer: fix bug in ring_buffer_discard_commit ftrace: do not profile functions when disabled tracing: make trace pipe recognize latency format flag ...
| * | | tracing/events: move trace point headers into include/trace/eventsSteven Rostedt2009-04-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: clean up Create a sub directory in include/trace called events to keep the trace point headers in their own separate directory. Only headers that declare trace points should be defined in this directory. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | tracing: create automated trace definesSteven Rostedt2009-04-141-2/+0
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch lowers the number of places a developer must modify to add new tracepoints. The current method to add a new tracepoint into an existing system is to write the trace point macro in the trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or DECLARE_TRACE, then they must add the same named item into the C file with the macro DEFINE_TRACE(name) and then add the trace point. This change cuts out the needing to add the DEFINE_TRACE(name). Every file that uses the tracepoint must still include the trace/<type>.h file, but the one C file must also add a define before the including of that file. #define CREATE_TRACE_POINTS #include <trace/mytrace.h> This will cause the trace/mytrace.h file to also produce the C code necessary to implement the trace point. Note, if more than one trace/<type>.h is used to create the C code it is best to list them all together. #define CREATE_TRACE_POINTS #include <trace/foo.h> #include <trace/bar.h> #include <trace/fido.h> Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with the cleaner solution of the define above the includes over my first design to have the C code include a "special" header. This patch converts sched, irq and lockdep and skb to use this new method. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | signals: implement sys_rt_tgsigqueueinfoThomas Gleixner2009-04-301-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_kill has the per thread counterpart sys_tgkill. sigqueueinfo is missing a thread directed counterpart. Such an interface is important for migrating applications from other OSes which have the per thread delivery implemented. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Roland McGrath <roland@redhat.com> Acked-by: Ulrich Drepper <drepper@redhat.com>
* | | signals: split do_tkillThomas Gleixner2009-04-301-12/+18
|/ / | | | | | | | | | | | | | | Split out the code from do_tkill to make it reusable by the follow up patch which implements sys_rt_tgsigqueueinfo Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Oleg Nesterov <oleg@redhat.com>
* | signals: SI_USER: Masquerade si_pid when crossing pid ns boundarySukadev Bhattiprolu2009-04-021-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When sending a signal to a descendant namespace, set ->si_pid to 0 since the sender does not have a pid in the receiver's namespace. Note: - If rt_sigqueueinfo() sets si_code to SI_USER when sending a signal across a pid namespace boundary, the value in ->si_pid will be cleared to 0. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | signals: protect cinit from blocked fatal signalsSukadev Bhattiprolu2009-04-021-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally SIG_DFL signals to global and container-init are dropped early. But if a signal is blocked when it is posted, we cannot drop the signal since the receiver may install a handler before unblocking the signal. Once this signal is queued however, the receiver container-init has no way of knowing if the signal was sent from an ancestor or descendant namespace. This patch ensures that contianer-init drops all SIG_DFL signals in get_signal_to_deliver() except SIGKILL/SIGSTOP. If SIGSTOP/SIGKILL originate from a descendant of container-init they are never queued (i.e dropped in sig_ignored() in an earler patch). If SIGSTOP/SIGKILL originate from parent namespace, the signal is queued and container-init processes the signal. IOW, if get_signal_to_deliver() sees a sig_kernel_only() signal for global or container-init, the signal must have been generated internally or must have come from an ancestor ns and we process the signal. Further, the signal_group_exit() check was needed to cover the case of a multi-threaded init sending SIGKILL to other threads when doing an exit() or exec(). But since the new sig_kernel_only() check covers the SIGKILL, the signal_group_exit() check is no longer needed and can be removed. Finally, now that we have all pieces in place, set SIGNAL_UNKILLABLE for container-inits. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Roland McGrath <roland@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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